Molar mass-dependent profiles of functional groups and carbohydrates in kraft lignin

Zinovyev, Grigory; Sumerskii, Ivan; Korntner, Philipp; Sulaeva, Irina; Rosenau, Thomas; Potthast, Antje

doi:10.1080/02773813.2016.1253103

Cited by 28 publications

(37 citation statements)

References 43 publications

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“…The above results are in agreement with Potthast et al . who, in a series of sequential ultrafiltration experiments of Kraft lignins from black liquor, found that aliphatic‐OH group content decreased, and both carboxyl and phenolic‐OH group content increased with decreasing molecular weight.…”

Section: Resultssupporting

confidence: 92%

“…Hence, it appears that, during the depolymerization process, low molecular weight DHL was produced as a result of cleavage of β ‐O‐4 and α ‐O‐4 linkages. As a result, more non‐condensed phenolic hydroxyl structures were generated . This is also confirmed in Figs and , where an increase in non‐condensed phenolic hydroxyls groups was observed with decreasing M w for both WL/HL ratios.…”

Section: Resultssupporting

confidence: 79%

“…An insignificant amount of condensed structures such as diphenylmethane, 4-O-5', and 5-5' was found in depolymerized hydrolysis lignin. 25 The above results are in agreement with Potthast et al 29 who, in a series of sequential ultrafiltration experiments of Kraft lignins from black liquor, found that aliphatic-OH group content decreased, and both carboxyl and phenolic-OH group content increased with decreasing molecular weight.…”

Section: Effect Of Temperature and Wl/hl Ratio On Depolymerized Lignisupporting

confidence: 89%

“…As a result, more non-condensed phenolic hydroxyl structures were generated. 29 This is also confirmed in Figs 6 and 7, where an increase in non-condensed phenolic hydroxyls groups was observed with decreasing M w for both WL/HL ratios.…”

Section: Effect Of Temperature and Wl/hl Ratio On Depolymerized Lignisupporting

confidence: 78%

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A novel environmentally friendly process for depolymerization of hydrolysis lignin using Kraft cooking liquor: chemicals recoverable by the Kraft recovery cycle

Ahmad

Gagné

Rio

et al. 2020

Biofuels Bioprod Bioref

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Hydrolysis lignin (HL) refers to a lignin‐rich residue obtained after the enzymatic hydrolysis of biomass. It is recalcitrant, heterogeneous, insoluble in most common solvents, and less reactive than other lignins. To enhance the reactivity of HL, a novel environmentally friendly depolymerization approach was demonstrated to produce depolymerized hydrolysis lignin (DHL) using Kraft cooking liquor, white liquor (WL) – recoverable by the Kraft recovery cycle. The effects of various process parameters such as reaction time, WL/HL ratio, and reaction temperature on lignin depolymerization were investigated using a 2 L Parr reactor under N2. The DHLs obtained were then characterized by Gel permeation chromatography (GPC)‐Ultraviolet Detector (GPC‐UV), 31P Nuclear Magnetic Resonance (NMR) spectroscopy, and ultraviolet visible (UV–visible) spectroscopy, while the filtrates were characterized by high‐performance liquid chromatography (HPLC) for saccharinic acids. The DHL yield reached 45–70% from the treatments at 150–190 °C for 1 h at a WL/HL mass ratio of 1:4 ~ 2:1. The weight‐average molecular weight (Mw) value of the DHL obtained at 190 °C after treatment for 1 h at a WL/HL ratio of 2:1 (w/w) was 2600 Da. Moreover, a significant increase in non‐condensed phenolic hydroxyl and carboxylic acid group content was observed with decreasing Mw. Compared with various existing lignin modification approaches, the approach reported here is less expensive and more environmentally friendly if integrated into Kraft pulp mill operations with the residual WL from the lignin depolymerization process being recycled to the mill chemical recovery cycle. Process scale‐up was also demonstrated using a 20 L circulating reactor. In this case, the Mw of the DHL produced after treatment at 170 °C for 2 h was 2400 Da. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd.

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Section: Resultssupporting

confidence: 92%

Section: Resultssupporting

confidence: 79%

Section: Effect Of Temperature and Wl/hl Ratio On Depolymerized Lignisupporting

confidence: 89%

Section: Effect Of Temperature and Wl/hl Ratio On Depolymerized Lignisupporting

confidence: 78%

See 2 more Smart Citations

A novel environmentally friendly process for depolymerization of hydrolysis lignin using Kraft cooking liquor: chemicals recoverable by the Kraft recovery cycle

Ahmad

Gagné

Rio

et al. 2020

Biofuels Bioprod Bioref

View full text Add to dashboard Cite

show abstract

“…As shown above by FTIR, this increase is likely to occur as a result of cleavage of ether linkages (β- O -4, α- O -4, etc.) during lignin depolymerization [ 38 ]. For example, in the DKL sample from Run #H9 with a M w = 1185 Da, the non-condensed phenolic group content is 7.8 mmol/g while for the control it is only 3.4 mmol/g.…”

Section: Resultsmentioning

confidence: 99%

Effects of Process Parameters on Hydrolytic Treatment of Black Liquor for the Production of Low-Molecular-Weight Depolymerized Kraft Lignin

et al. 2018

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The present research work aimed at hydrolytic treatment of kraft black liquor (KBL) at 200–300 °C for the production of low-molecular-weight depolymerized kraft lignin (DKL). Various process conditions such as reaction temperature, reaction time, initial kraft lignin (KL) substrate concentration, presence of a catalyst (NaOH), capping agent (phenol) or co-solvent (methanol) were evaluated. The research demonstrated effective depolymerization of KL in KBL at 250–300 °C with NaOH as a catalyst at a NaOH/lignin ratio of about 0.3 (w/w) using diluted KBL (with 9 wt. % KL). Treatment of the diluted KBL at 250 °C for 2 h with 5% addition of methanol co-solvent produced DKL with a weight-average molecular weight (Mw) of 2340 Da, at approx. 45 wt. % yield, and a solid residue at a yield of ≤1 wt. %. A longer reaction time favored the process by reducing the Mw of the DKL products. Adding a capping agent (phenol) helped reduce repolymerization/condensation reactions thereby reducing the Mw of the DKL products, enhancing DKL yield and increasing the hydroxyl group content of the lignin. For the treatment of diluted KBL (with 9 wt. % KL) at 250 °C for 2 h, with 5% addition of methanol co-solvent in the presence of NaOH/lignin ≈ 0.3 (w/w), followed by acidification to recover the DKL, the overall mass balances for C, Na and S were measured to be approx. 74%, 90% and 77%, respectively. These results represent an important step towards developing a cost-effective approach for valorization of KBL for chemicals.

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Wood Adhesives Based on Natural Resources: A Critical Review: Part III. Tannin‐ and Lignin‐Based Adhesives

Dunky

2021

Progress in Adhesion and Adhesives

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Molar mass-dependent profiles of functional groups and carbohydrates in kraft lignin

Cited by 28 publications

References 43 publications

A novel environmentally friendly process for depolymerization of hydrolysis lignin using Kraft cooking liquor: chemicals recoverable by the Kraft recovery cycle

A novel environmentally friendly process for depolymerization of hydrolysis lignin using Kraft cooking liquor: chemicals recoverable by the Kraft recovery cycle

Effects of Process Parameters on Hydrolytic Treatment of Black Liquor for the Production of Low-Molecular-Weight Depolymerized Kraft Lignin

Wood Adhesives Based on Natural Resources: A Critical Review: Part III. Tannin‐ and Lignin‐Based Adhesives

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